Electromagnetic relay



Oct, 10, 1939. c.- H. LARSON 75,201

ELECTROMAGNETIC RELAY Filed Jgne l, 1936 3 Sheets-Sheet l Oct. 10, 1939. c. H. LARSON 2,175,201v

ELECTROMAGNETIC RELAY Filed June 1, 1936 3 Sheets-Sheet 2.;

1939- c. H. LARSON ELECTROMAGNETIC RELAY Filed June 1, 1936 3 Sheets-Sheet 3 IIIM 90 0771507 L arson Ca/d H M Mia/Q Patented Qct 10,1939

PATENT OFFICE ELECTROMAGNETIC RELAY can a. Larson, Elkhart, Ind., assignor to The Adlake Company, a corporation of Illinois 'Application June 1, 1930, Serial No. c2554 a Claims. (01. zoo-91) It is very diflicult in electro-mechanical relays a to operate a series of electrical contacts at difi'erent time intervals after the happening of a particular event, as for example the energizing oi the relay coil, and usually it is necessary to moving parts are enclosed within a hermetical y sealed casing; in which the timing action when once adjusted is constant and unchanged; in which the contacts are capable of carrying heavy loads and standing up under long periods of service; and in which the contacts maybe subject to relatively large difierences in time delay action. Further and other objects and advantages will become apparent as thedis'ciosure proceeds and the description is read in conjunction with the accompanying drawings. in which: Fig. 1 is a partially diagrammatic view of a relay made in accordance with this invention, the parts being shown in the pontion which they occupy immediately after the control switch hasiunctioned and before the main switch has had an opportunity to function.

Fig. 2 is a view showing the position of the switch parts immediately after the armature has beendrawn dbwnwardly within the switch en- Fig. 3 is aview corresponding to Fig. 1, but in this view, the parts are shown in the position which they occupy immediately .after the control switch has been energized and before the armature of the main switch has had an opportunity to be restored to its normal position.

m. 4 shows a modified form of the invention in which the time delay electrodes are'responsive to the outside mercury level, and in which the control switch is made a part of the main switch 5 is a fragmentary view showing the relationship o! the electrodes to the mercury level at the instant when the central electrode comes in contact with the mercury;

= Fig. 6 shows the armature in its upper position after the central or control electrode recycled theswitch; I,

Pig. 7 is a i entary," sectional view a 1 modified form of the invention; and v Fig. 8 is a fragmentary, sectional view taken on the line 8-8 01' Fig. 7.

For the purpose of complying with section 4888 of the Revised Statutes, several preferred embodiments of the invention have been disclosed in conjunction with anelectiically illuminated advertising sign. It will be understood, however, that the specific embodiments of the invention chosen for description and illustration are merely examples of the many ways in which the invention herein disclosed may be embodied within the scope of the appended claims. The claims, therefore, are to be construed as broadly as the prior art will permit.

Assuminsthe advertising sign to be controlled consists of three units, for example A 8: W", it is possible to operate the sign (among other ways) by first illuminating the letter A, then 8: and finally W", after which all three units are extingulshed, ready for the sequence to be repeated, or the three units may be illuminated simultaneously and then the A extinguished, then 8: and finally "W.

The main switch Ill and control switch ll shown in Figs. 1 and 3 are capable of accomplishing the first alternate and the switch shown in Figs..4, 5, and 6 is capable of accomplishing the second alternate. I s

Referring now to Fig. 1, the sign units are indicated at, l3 and I4, and each has a lead 7 connecting through a conductor IS with one side,

for example the negative side, of a battery or other source of electro-motive force l6. Conductors l1, II and 19 leading from the respective units, 'are connected, respectively,.to electrodes 20, 2| and 22 which are sealed through thebase oi a mercury switch envelope 23 which contains a quantity of mercury 24, a mercury displacer, generally designated 25, and an inert gas fill indicated at 26, the latter being introduced into the envelope after it has first been evacuated. Preferably, the envelope 23 is made of a boro-silicate glass, such as 733A made by the Coming Glass Works of Coming, New York, and the electrodes 20, 2| and 22 are preferably of molybdenum.

A lead 21 from the relay coil 28 associated with the control switch H is connected to another the switch envelope, and all iour electrodes 20,

2i, 22 and 29 are insulated from each other difierent heights with respect to the base of the electrode 29 similarly sealed through the base 01 gas to slowly escape through the envelope, these exposed portions being indicated at 32, 33, 34, and 35. The ceramic material 8i serves the purpose of resisting the deteriorating eifect of the electric are formed when the switch is carrying a comparatively heavy load.

d The displacer 25, which is shown more or less diagrammatically, comprises an iron sleeve 36 vertically slotted as indicated at 31 and having an opening in its upper wall into which a glass thimble 38 is fitted and held in place by a spring 39 tightly coiled over the projecting end of the thimble. Other means, may, of course, be employed for" holding the thimble within the sleeve 36.

' The thimble 38 is preferably made of 733A glass and has a relatively small opening 48 into which a plug 4! of ceramic material is fused. When 733A glass is used for the thimble 38, the ceramic material is preferably Alundum (Grade RA 84, RA 360 or RA 98) a product of the Norton Company, Worcester, Massachusetts, as this material fuses readily'wlth 733A glass.

In order to give the displacer greater buoyancy, a ceramic liner 42 may be provided in the lower'end of the displacer, and a spring 43 tightly coiled on the projecting end of the liner serves to hold the liner in place and protect the switch envelope. a

The'switch i 8 is operated by a relay coil 44 having an iron circuit 45 associated with it which includes pole sleeves 46 and 41 separated by an air gap which in this case is occupied by a split sleeve 48 of non-magnetic material. The sleeve 48 has suflicient resiliency to grip the tube 28 and hold it in adjusted position.

The coil 44 associated with the switch I8 is connected by conductors 49 and 88 with the.

electrodes 5] and 52, respectively, of the control switch II, the latter being a mercury switch of the same general type as the main switch i8, and comprising a switch envelope 53, a mercury fill 54, a displacer 55, the upper portion 580! which is of magnetic material, and the lower portion 51 of which is in the form of an impervious glass thimble which displaces a suflicient amount of mercury when the displacer is in its lowermost position to cover the bared end 88 of the electrode 52, but displaces an insufficient amount of mercury when the displacer is raised by, energization of the relay coil 28 to bridge the electrodes 5| and 52 with mercury.

Thus, when the relay coil 28, associated with the control switch II, is tie-energized, the main switch coil 44 is energized (a battery 58 or the like being provided for supplying the electromotive force) and when the relay coil 28 is energized, the main switch coil 44 is de-energized.

Assuming the parts of the'maln switch l8 to be in the position in which they are shown in Fig. l, and that the relay coil 28 associated with the control switch H has just been energized, the displacer 25 of the main switch will be drawn downwardly to close the air gap between the pole sleeves 46 and 41 and as this takes place, the thimble 38 will entrap a certain amount of gas and force mercury away from the exposed electrodes 32, 33, 34, and 35 (see Fig. 2). The sign units at this moment are obviously not illuminated. The gas pressure created within the thimble 38, due to the diil'erence of mercury levels. within and on the outside of the thimble, causes porous plug 4! and as the-pressure tends to become equalized, the mercury level on the inside of the thimble will slowly rise while that on the outside slowly the outside mercury constantly in contact with the mercury. When the circuit through the electrodes 82 and 88 is closed, the sign unit I2 is illuminated. As the mercury level continues to rise, the electrodes 88 and 34 are successively placed in electrical connection with the common electrode 88, thus successively illuminating the sign units i 3 and I4. When the mercury level reaches the electrode 35, the coil 28 associated with the control switch ii is energized, thereby breaking the electrical circuit through the main switch coil 44, allowing the displacer 25 to rise by buoyancy to the position shown in Fig. 1. The mercury that is carried up within the thimble 38 as the displacer rises, falls away from the thimble as soon as the lower edge of the thimble 38, reaches a point above level. At this instant,-the circuit throughthe electrodes 32, 83, 34 and is broken and the sign units l2, l3 and I4 are extinguished. At the same time, the coil 28 associated with the control switch II is deenergized allowing the displacer 55 to fall by gravity to the position shown in Fig. 1, thereby reenergizing the main switch coil 44 and starting the cycle once more.

The position of the switch parts in Fig. 3 is at the instant when the control relay has been energized, thereby breaking the electrical circuit through the main switch coil 44, but before the main switch displacer 25 has had an opportunity to rise to the position shown in Fig. 1.

The relay shown in Figs. 4, 5 and 6 has the the control switch incorporated into the main switch, but it will be understood that a separate switch may be used if desired.

The electrodes l2,' l3 and I4 are subject to the outside mercury level and are indicated at I8, H and 12. They are sealed through the base of the switch envelope 13, together with a central electrode 14 and a common electrode 15. Insulating sleeves,

generally indicated at 16 surround the electrodes 18, ll, 12 and 14 for a portion of their height and as before, ceramic sleeves cap the glass sleeves 18 to better withstand the ravages oi. the electric are when the circuits are being opened and closed.

The switch envelope 13 may be provided with a vertical protuberance '11 to accommodate the electrodes 18, 1| and 12, and a displacer i8 is reciprocable within the switch envelope in response to a relay coil 19 to shift the mercury fill 88, and thereby cover and/or uncover one or more electrodes.

The displacer 78 (shown somewhat diagrammatically) consists of an iron armature 8| telescoped over a glass thimble 82 provided with a porous wall 83 fused into the top wall of the thimble. Guide rings 84 are provided on the displacer to position the armature within the envelope and coil springs 85 hold the rings in place.

An iron circuit, generally designated 88, is associated with the coil 18 and it includes pole sleeves 81 and 88 spaced apart to provide an air gap 89 which the armature 18 tends to span when the relay coil 19 is energized.

The sign units i2, i3 and H are connected through a conductor 98 with one side of a battery 9!, or other source of electromotive force.

which control the sign units been extingu shed the top of the sleeve forcing mercury away and the other side of the battery is connected as the common electrode 15. This latter electrode is also connected through a conductor 02 with the relay coil ll, the other lead 93 from the coil being connected to the central electrode 14 through a battery 04.

when the coil I! is energized (see Fig. 5) the displacer I0 is immediately lifted to the position shown in Fig. 6 at which time the electrodes I0, II, II and 14 are out of contact with the mercury. Since the latter electrode controls the energization of the coil 19, the action of the displacer in risingto the position shown in Fig. 6 actually de-energizes the coil 10 and it falls bygravity to the position shown in Fig. 4, forcing the outside mercury level immediately above the tallest electrode 10 and at the same time from the central electrode 14 due to the entrapment of gas within the thimble 02. As gas slowly escapes through the porous plug 03, the mercury level slowly rises within the thimble and at the same time, there is a corresponding lowering of the outside mercury level. Obviously, the fall of the displacer functions to immediately illuminate the entire advertising sign and when the outside mercury level falls below the top of the insulating sleeve surrounding the electrode 10, the unit I! will be extinguished. Shortly thereafter (the length of time depending upon the porosity of the time delay element 03) the unit I3 will be extinguished and still later, the unit II. when the unit ll has (but not until then) the mercury level on the inside of the displacer reaches electrode I4 and thereby closes the circuit through the coil 19. when this takes place, the displacer I0 is lifted to the position shown in Fig. 6, and since the thimble is lifted completely out 01' the mercury, the latter falls away quickly fromthe interior of the thimble, leaving all of the electrodes uncovered whereupon the switch repeats its cycle.

It will be understood thatthe length oi the time interval between the opening and/or closing of the several circuits maybe varied within relativeLy large limits by proper selectlon'oi the mercury fill, height of insulating sleeves, and the material used for the time delay element. when it is desired to have the electrodes subjectto greater selection and still greater range of time control, an arrangement such as shown in Figs.

7 and 8 (byway of illustration) may be used.

As shown in Fig. '1, a plurality of electrodes I00, IUI III, I00 and I04 may be sealed through the base of a switch envelope I05, each being provided with an lnsulatingsleev such as indicated at I". ,The electrodes are formed so that their ends are arranged as shown in Fig. 8. The central electrode I02 supports a molded ceramic time delay element, generally designated I01, which has :a central pocket I00 and a plurality oi radial chambers I 09, each of which receives one of the electrodes.

An iron armature IIO moving in response to a ,coil shifts the mercury level so as to close the bottom of the. element I01 with mercury and establish a pressure diflerential between the interlor of the element and the exterior. The rate oi gasflow between the several chambers oi the time delay-element I01 may be controlled by the relative sizes of the chambers, the material used ior the individual chambers, by applying dabs of cement to portions of the time delay element to vary'the porosityof that particular portion switch associated-with the surrounding the centraltrodes when the fill in the condition of said circuits.

of the element, or by other suitable means. Also the relative effective time delay between the several electrodes may be controlled by properly selecting the height of the insulating sleeves I06. By way of example, the sleeve around the electrode I00 is longer than that around the electrode IOI,so that if the chamber associated with the electrode I00 is identical with the one associated with the electrode I00, the latter will not make contact with the mercury until after the electrode I03 has made contact.

It is, of course, understood that in the specific illustrations of Fig. '7, each of the insulated electrodes completes its respective circuit through a common electrode III.

One of the outstanding advantages'oi this invention is the great number and variety of time delay effects which may be introduced intoa single relay. Obviously, therefore, the invention may be variously embodied within the appended claims.

Instead of having the relay coils lower the displacers, the switches may be built so that the coils lift the armatures and gravity lowers them.

I claim: a

1. In a mercury switch relay, a relay coil, a cell comprising a switch envelope, a plurality of electrodes in the envelope, a mercury fill, means responsive to the coil for shifting the fill into contact with, or out of contact'with, at least two of said electrodes, depending on the direction of movement of the fill and time delay means for retarding the movement' of at least a portion of the mercury fill in the vicinity of said two electrodes, said time delay means and said two electrodes cooperating to effect successive like changes in the electrical contact relationship between the fill and said two electrodes.

2. In a mercury switch relay, a relay coil, a mercury switch associated with the coil comprising a switch envelope, a plurality of electrodes in the envelope, a mercury fill, means responsive to the coil for shifting the fill in a given direction and time delay means in the envelope associated with two of the electrodes and-adapted to eiIect successive like changes in the'electrical contact relationship between the fill and said two elec- 3. In a mercury switch relay, a relay coil, a mercury switch associated with the cell including a plurality of electrodes and a quantity of mercuryadapted to be moved to and from contact with said electrodes, and. means for delaying the movement of at least\a portion of the mercury whereby the like condition of the electrical circuits through two of the electrodes and a third electrode in the switch is successively changed to other like conditions after the lapse of a given time interval from the operation of the relay coil.

4. In a mercury switch relay, a relay coil, a switch associated with the coil comprising a switch envelope, a plurality of electrodes in the envelope, a mercury 1111, a magnetically responsive displacer for shifting the fill to change the condition of the electrical circuits through two of said electrodes and a third electrode inthe switch, and time delay means telescoped over said two electrodes for retarding the movement of at least a portion ofthe mercury fill in the vicinity of said two electrodes, said means and said two is shifted in said direction.

electrodes cooperating to eflect successive changes 5. In a-mercury switch relay, a relay coil,,a switch associated with the coil comprising a switch envelope. a plurality of electrodes in the envelope at difierent heights with respect to the envelope base, a mercury fill, means'responsive to the coil for shifting the fill to change the condition of the electrical circuits between two of the electrodes and a third electrode in the switch, and time delay means associated with said two electrodes for retarding the movement of at least a portion of the mercury fill in the vicinity of said two electrodes 7 in the condition of the respective circuits are effected. 4 i

6. In a mercury switch relay, a relay coil, a switch associated with the coil comprising a switch envelope, a group of electrodes in the en- Velope at diiferent heights with respect to the envelope base, a mercury fill means instantaneously responsive to the coil for shifting the fill to change-the condition of'the electrical circuits between two of the electrodes and a third electrode in the switch, and time delay means associated with said two electrodes for retarding the movement of a portion of the fill in the vicinity of said two electrodes whereby successive changes in the condition of\ said respective circuits controlled by said two fected.

, 7. In a mercury switch relay, a relay coil, a mercury switch associated with the coil including a switch envelope, a group of electrodes, and a quantity of mercury adapted to be moved to and from contact with said electrodes, and means electrodes are ei'- whereby successive changes for delaying the movement of at least a portion of the mercury whereby the like condition of the electrical circuits through two of the electrodes and a third electrode in the switch is successively changed to other like conditions for the lapse of a given time interval from'the operation of the relay coil, said means including a gas restricting element telescoped over the exposed portions of the electrodes and provided with a plurality of separate pockets each 01 which receives one electrode, each pocket being provided separately with means for restrictively passing gas between the interior of the pocket and the chamber surrolmding the pocket at a predetermined rate of speed.

8. In a mercury switch relay, a relay coil, 9. switch associated with the coil including a switch envelope, .a plurality of electrodes in the envelope at different heights with respect to the envelope base, a mercury fill, a displacer surrounding the electrodes being responsive to the coil for shifting the fill to change the condition of the electrical circuits between two of the electrodes and a third electrode in the switch, and time delay 1 means fixed with respect to the displacer and as-' sociated with said two electrodes for retarding the movement of at least a portion of the mercury fill in the vicinity of said two electrodes whereby successive changes in the condition of the respective circuits are eflected.

CARL H. LARSONQ 

